Caffeine has a half-life that can range from 4 to 10 hours. In extremely high doses or overdose, the half-life may be as long as 15 hours. Some individuals with polymorphisms CYP1A2 isoenzyme, and pregnant women may have a prolonged clearance (slow metabolizers). Tobacco smoking accelerates caffeine metabolism and possibly smoking cannabis as well.
Caffeine-containing herbs include the well-known Coffee (Coffea species), the various forms of tea (Camillia sinensis) and the often desired Chocolate (Theobroma cocao). But don’t overlook Kola nut (Cola nitida or C. acuminata), Yerba Mate (Ilex paraguariensis) and Guarana (Paullinia cupana).
While coffee is often thought of as the main source for caffeine in the US, it does contain chlorogenic acid, the 2nd highest constituent after caffeine, and one of the most consumed polyphenols in the US diet. Chlorogenic acid may be one of the reasons that recent studies have shown coffee to be beneficial to prevent the onset of T2DM. Chlorogenic acid activates the adenosine monophosphate-activated protein kinase (AMPK) pathway, considered a main regulator of metabolism and a primary target for the treatment of T2DM.
Another constituent of coffee is the alkaloid trigonelline, a compound significantly responsible for coffee’s bitter taste and aroma. It is found in higher amount in Coffea arabica beans. The combination of trigonelline and chlorogenic acid, has been studied in humans to reduce insulin responses during an OGTT. Trigonelline has also been described as a phytoestrogen.
For those clinicians and patients who are looking for caffeine-free options for hot beverages there are several herbal options. Tulsi or Holy Basil teas are available at many health food stores and come in various herbal combinations for different flavors. The traditional herbal teas of the southern Africa region are very popular. Rooibos or red bush tea (Aspalathus linearis) and Honeybush tea (Cyclopia intermedia) are both from the Fabaceae or legume family. Rooibios has significant antioxidant activity and has been described as a “mixture of honey, woody, and herbal-floral flavors with a slightly sweet taste and a subtle astringent mouthfeel.” Honeybush tea has a range of phytoestrogens including formononetin and coumestans as well as antioxidant polyphenols. , For those who want to flavor of coffee or tea without the caffeine, supercritical CO2 extracts are becoming more available. This would be a good way to get the benefits of the various forms of tea (Camellia sinensis) without chemical residues.
Enjoyable as many caffeine products are, clinicians and patients should evaluate usage in terms in the endocrine system, discuss pros and cons of specific forms and the amount consumed to find alternatives or limit use if needed.